NASA discovers 715 new planets but no aliens — yet

The artist concept depicts multiple-transiting planet systems, which are stars with more than one planet. The planets eclipse or transit their host star from the vantage point of the observer. This angle is called edge-on.
— NASA

The artist concept depicts multiple-transiting planet systems, which are stars with more than one planet. The planets eclipse or transit their host star from the vantage point of the observer. This angle is called edge-on.
/ NASA

NASA got scientists and nerds (like me) and pretty much the entire Internet excited Wednesday with a stunning announcement that its Kepler mission had discovered 715 new planets orbiting 305 stars.

No word yet on whether aliens might be among us. But life might be able to exist on four of these planets.

A blog post on nasa.gov explained that "Nearly 95 percent of these planets are smaller than Neptune, which is almost four times the size of Earth." A far smaller number — four, to be exact — may support life. Specifically, these planets are "less than 2.5 times the size of Earth and orbit in their sun's habitable zone, defined as the range of distance from a star where the surface temperature of an orbiting planet may be suitable for life-giving liquid water."

NASA put its discovery — the largest windfall of planets ever — in context, declaring it "marks a significant increase in the number of known small-sized planets more akin to Earth than previously identified exoplanets, which are planets outside our solar system." Those first planets outside our solar system were discovered about two decades ago. The new batch brings the total planet count to nearly 1,700, NASA said, before getting as philosophical as any government press release ever: "As we continue to reach toward the stars, each discovery brings us one step closer to a more accurate understanding of our place in the galaxy."

If you're wondering about space travel to new worlds, NASA has you covered. Its post declares: "Launched in March 2009, Kepler is the first NASA mission to find potentially habitable Earth-size planets. Discoveries include more than 3,600 planet candidates, of which 961 have been verified as bona-fide worlds."

NBC reported that the Kepler mission costs $600 million and shared this detail that NASA neglected to mention in its post:

"Kepler's planet search had to be suspended last May when the spacecraft's fine-pointing system failed, and it's not yet clear whether it can be returned to service. But MIT astronomer Sara Seager said hundreds more planets, including Earth-scale worlds, could be found in the data already collected for the mission."

The discovery calls to mind this quote from futurist and author Arthur C. Clarke:

Sometimes I think we're alone in the universe, and sometimes I think we're not. In either case the idea is quite staggering.